Schedule your Radon
Inspection with your Home Inspection
is Radon? Radon
is a gaseous radioactive element having the symbol Rn, the atomic number 86, an
atomic weight of 222, a melting point of -71ºC, a boiling point of -62ºC, and
(depending on the source, there are between 20 and 25 isotopes of radon - 20
cited in the chemical summary, 25 listed in the table of isotopes); it is an
extremely toxic, colorless gas; it can be condensed to a transparent liquid and
to an opaque, glowing solid; it is derived from the radioactive decay of radium
and is used in cancer treatment, as a tracer in leak detection, and in
radiography. (From the word radium, the substance from which it is derived.)
Sources: Condensed Chemical Dictionary, and Handbook of Chemistry and Physics,
69th ed., CRC Press, Boca Raton, FL, 1988.
Where does radon come from? Radon-222
is the radioactive decay product of radium-226, which is found at low
concentrations in almost all rock and soil. As radon is generated in rock and
soil it creeps up to the outside air. Although
outdoor concentrations of radon are typically low, about 0.4 picocuries per
liter (pCi/l) of air, it can seep into buildings through foundation cracks or
openings and build up to much higher concentrations indoors.
Who discovered radon was a problem in our homes?
itself was first discovered by scientists around 1900. It wasn’t until 1984 when a nuclear plant worker in Pennsylvania set
off the radiation detectors leaving the plant that the medical community
nationwide became aware of radon in our homes. Investigation revealed the radiation was from radon in the workers home!
average national indoor radon concentration is about 1.3 pCi/l of air. It is not
uncommon for indoor radon levels to be found in the range of 5 - 50 pCi/l, and
they have been found as high as 2,000 pCi/l.
concentration of radon measured in a house depends on many factors, including
the design of the house, the heating and ventilation systems, local geology and
soil conditions, and the weather.
Radon is the second leading cause of lung cancer.
is no safe level of radon--any exposure poses some risk of cancer. In two 1999
reports, the National Academy of Sciences (NAS) concluded after an exhaustive
review that radon in indoor air is the second leading cause of lung cancer in
the U.S. after cigarette smoking. The NAS estimated that 15,000-22,000 Americans
die every year from radon-related lung cancer. That’s 10% of all lung cancer deaths annually.
alpha radiation from radon and its decay products cause damage to sensitive lung
tissue. Most of the radiation dose is not actually from radon itself, but rather
from radon's chain of short-lived solid decay products that are inhaled and
lodge in the airways of the lungs. These radionuclides decay quickly, producing
other radionuclides that continue damaging the lung tissue. Those particles that are retained long enough release radiation damaging
surrounding lung tissues. It is
this damage that causes lung cancer.
Smokers, former smokers, & second-hand smokers are at increased risk.
decay products also cling to tobacco leaves, which are sticky, during the
growing season, and enter the lungs when tobacco is smoked.
in indoor environments also is very effective at picking up radon decay products
from the air and making them available for inhalation. It is likely that radon
decay products contribute significantly to the risk of lung cancer from
What about children...are they at increased risk? Children
have been reported to have greater risk than adults for certain types of cancer
from radiation, but there is currently no conclusive data on whether children
are a greater risk than adults from radon.
radon exposure should start as early as possible.
How do we know radon is
a carcinogen? The
World Health Organization (WHO), the National Academy of Sciences, the US
Department of Health and Human Services, as well as the US EPA, have classified
radon as a known human carcinogen because of the wealth of biological and
epidemiological evidence and data showing the connection between exposure to
radon and lung cancer in humans.
have been many studies conducted by many different organizations in many nations
around the world to examine the relationship of radon exposure and human lung
cancer. The largest and most recent of these was an international study, led by
the National Cancer Institute (NCI), which examined the data on 68,000
underground miners who were exposed to a wide range of radon levels. The studies
of miners are very useful because the subjects are humans, not rats, as in many
cancer research studies. These miners are dying of lung cancer at 5 times the
rate expected for the general population. Over many years scientists around the
world have conducted exhaustive research to verify the cause-effect relationship
between radon exposure and the observed increased lung cancer deaths in these miners and to eliminate other possible causes.
addition, there is an overlap between radon exposures received by miners who got
lung cancer and the exposures people would receive over their lifetime in a home
at EPA's action level of 4 pCi/L, i.e., there are no large extrapolations
involved in estimating radon risks in homes.
are the chances of dying from lung cancer caused by radon? Radon
exposure significantly increases your risk of dying from lung cancer, but just
as not everyone who smokes will get lung cancer, not everyone exposed to high
levels of radon will get lung cancer. The
following is the “EPA Assessment of Risks from Radon in Homes” an updated
chart of the lifetime risk of lung cancer death per person from radon exposure
in homes. The full text of the
updated risk assessment, “EPA Assessment of Risks
from Radon in Homes” (EPA 402-R-03-003) is available as a downloadable
Adobe Acrobat file.
Can a medical test tell what someone’s exposure has been or how much damage has
decay products can be detected in urine, blood, and lung and bone tissue.
However, these tests are not generally available through typical medical
facilities. Also, they cannot be used to determine accurate exposure levels,
since most radon decay products deliver their dose and decay within a few hours.
Finally, these tests cannot be used to predict whether a person's exposure will
cause harmful health effects, since everyone's response to exposure is
best way to assess exposure to radon is by measuring concentrations of radon (or
radon decay products) in the air you breathe at home.
above information was provided by Radon Detection Specialists,
the provider of our radon testing services.
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